The present invention relates to a side vehicle body structure, and more particularly, relates to a side vehicle body structure of a vehicle, which is provided with a shoulder anchor part for a seat belt.
In a side vehicle body structure of a general vehicle, as seat belt attachment parts, a shoulder anchor part and a retractor anchor part are provided, and the shoulder part is provided on a quarter panel made of a thin sheet. A vehicle having such a side vehicle body structure is configured so that, when a load is applied from the vehicle front, the side vehicle body structure receives a high load applied to the shoulder anchor part and the retractor anchor part. However, the quarter panel made of a thin sheet cannot sustain the load applied to the shoulder anchor part.
Therefore, as described in Patent Document 1, some conventional side vehicle body structure has employed a structure in which a reinforcement having a hut-shaped cross section is attached to the quarter panel on the vehicle outside (between the quarter panel and a side body outer panel) to form a U-shaped closed cross section, whereby the load applied to the shoulder anchor part is sustained.
Also, if a load is applied from the vehicle front, the inertia load of an occupant on a rear seat is received by the seat belt, the shoulder anchor receives a load in the slantwise downward direction of the vehicle front, and the shoulder anchor part is deformed to the vehicle front.
Therefore, as described in Patent Document 2, some conventional side vehicle body structure has secured, due to the quarter panel and a reinforcement (backing metal reinforcement), such a degree of strength that the shoulder anchor is not torn off the side vehicle body. To restrain the quarter panel from being deformed, countermeasures for absorbing the load have been taken by increasing the sheet thickness of the quarter panel to secure the rigidity of the quarter panel itself and by distributing the load by joining the quarter panel to other parts.
Alternatively, as described in Patent Documents 3 and 4, the load has been absorbed by arranging a member throughout in the up-and-down direction of the quarter panel to secure the rigidity of the side vehicle body and by joining the shoulder anchor to the member.    Patent Document 1: JP 2845061 B    Patent Document 2: JP 2007-296890 A    Patent Document 3: JP 2008-62748 A    Patent Document 4: JP 2008-238885 A
However, the increase in sheet thickness of the quarter panel as in the above-described conventional side vehicle body structure leads to an increase in the weight of the vehicle body and may exert an adverse effect on the fuel economy of the vehicle.
Also, the addition of a reinforcing part to the quarter panel as in the above-described conventional side vehicle body structures not only leads to an increase in the weight of the vehicle body, but also increases the labor for handling in the assembly process, which may lower the production efficiency.
Furthermore, in Patent Document 1, the structure of the retractor anchor part is not described, and the reinforcement having a hut-shaped cross section is located on the vehicle outside. Therefore, to receive and hold the load applied to the retractor anchor part, a separate part must be provided, which also presents a problem of increased weight of vehicle body and increased number of assembly processes.